It’s not that the unraveling of a third or fourth serial killer’s mind would freak me out, or that my eyes would start to look like glazed donuts. The limit just seems appropriate.

I do something similar at work, and it makes me think imposing arbitrary limits is my modus Knopferandi.

In the windowless News Bunker where I work, I deal with nervous, neurotic snacking by setting limits. For example, I keep a jar of peanuts in my desk. When gum or sugarless candy aren’t working, I fill the lid with peanuts and eat one at a time. When the lid’s empty, I put the jar back in the drawer until the next three-alarm nosh alert.

There’s no calorie counting to this and no science – unless you consider bargain-basement conditioning a scientific discipline.

I do the same with other things – peanut butter crackers, for example. I’ll eat three in the car (not six) on the way to work and chase it down with an apple. I usually eat the other three crackers on the way home.

Same goes for the sweet-potato chips or salted-in-the-shell peanuts I keep at work. I actually count out 10 of each, and that’s it, finis.

These arbitrary limits seem to work, but they’re not perfect and neither am I. If they were, I wouldn’t have taken weight off and put it back on a half-dozen times. If I were more machine-like and could maintain limits, I might keep the weight off permanently.

Then other neurotic behavior would probably pop up to compensate, but at least I’d be thin on the way to the psychologist.

When I was taking the weight off last time, I got in the habit of never going back for seconds at meal time. It helped to stick with one serving, a form of conditioning that over time became easier, like walking on a wooden leg with a parrot on your shoulder.

That’s not to say I wouldn’t catch myself eyeing the serving spoon in the lasagna or sometimes even gobbling down what was left on it in the name of a smoother cleanup.

When I’d done well with self-control during the week, my reward would be to step on the scale Saturday and see that the limits, arbitrary and otherwise, had brought results.

I’ve felt myself slipping a bit recently – an extra bite, another serving spoon, maybe a handful of peanuts rather than a lid-ful. Then, like clockwork, the perception that the weight’s returning hits me – real or imagined – and fretting about it only feeds the desire for nervous noshing.

You’d think that by repeating these arbitrary limits I could forge habits of steel, but it doesn’t work that way. Whatever it is that compels me to eat has an uncanny knack for exploiting hairline cracks in the willpower.

So it’s either re-invoke my mantra of strict arbitrary limits or give in.

That kind of black-and-white, all-or-nothing mentality isn’t fun to live with. For example, my son will ask me to try something – say a couple tater tots – and I’ll emphatically say no, as if they contain anthrax or the evil fat-boy gene (actually, with the latter, they do).

When I hold the line like that, it’s simply fear motivating me. Fear that a chink in the wall here, a chink in the wall there, and I’m back to the beginning, back to having to get up the resolve to set limits again.

And I’d rather watch a third whodunit than another been-there, done-that.